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.\" Copyright (c) 2024 Denis Bodor <dbodor@rollmops.ninja>
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.Dd February 18, 2024
.Dt I2CTINYUSB 4
.Os
.Sh NAME
.Nm i2ctinyusb
.Nd driver for a USB / I2C bridge device
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device i2ctinyusb"
.Cd "device usb"
.Cd "device iicbus"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
i2ctinyusb_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides support for the device designed by Till Harbaum known
as i2c-tiny-usb. This is initially a very simple circuit built with
an Atmel AVR ATtiny45, but a Raspberry Pi Pico (RP2040) implementation
also exists.
.Pp
The
.Nm
driver creates a
.Xr iicbus 4
child bus to expose the iic functions, enabling I2C sensors, converters
and displays to be connected to any computer with a USB port.
.Pp
More information about this device can be found at:
.Bd -literal -offset indent
https://github.com/harbaum/I2C-Tiny-USB
.Ed
.Pp
and (for the Raspberry Pi Pico version):
.Bd -literal -offset indent
https://github.com/Nicolai-Electronics/rp2040-i2c-interface
.Ed
.Pp
The I2C controller supports read and write transactions with up to 1024
bytes of data, and a write followed by the repeated start followed by a
read transactions up to 1024 bytes.
Zero length transfers are not supported.
.Sh SEE ALSO
.Xr iicbus 4 ,
.Xr usb 4
.Sh HISTORY
The
.Nm
driver and this manual page was written by
.An Denis Bodor Aq Mt dbodor@rollmops.ninja .
